Insertion envelopes are envelopes for letters and documents which are automatically filled with content in inserter machines. This means that they must be processed automatically in a very large numbers in very rapid succession. It is important in this case that the empty insertion envelopes to be filled are fed perfectly constantly in the same alignment, so that the filling mechanism provided in the inserter machine can also operate accordingly without occurrence of stoppages. Such stoppages would be extremely expensive, since they cause the entire filling and insertion process to stop and the personnel must intervene manually.
If such an insertion envelope to be filled is cause for such a stoppage, it is generally the case that not only the envelope itself but also the provided contents are crumpled or destroyed and the associated document or letter must therefore possibly be completely newly prepared. Since this must occur out of sequence and it must also be checked which document is concerned, significant additional costs arise here that are completely disproportionate to the actual value of the insertion envelope.
To ensure the subsequent feed of insertion envelopes for further processing, the supplied envelopes must be placed on a feed belt or in a feed channel, and in such a way that the feed mechanism can then perform the mentioned alignment simply and reliably. The insertion envelopes are then automatically conveyed on this feed belt or in this feed channel into the inserting machine and are filled and further processed, there.
Insertion envelopes are conventionally packed in cardboard boxes made of grey board or corrugated cardboard. As a result, a certain number of 750, 800 or 1000 envelopes, for example, can be respectively protected in one cardboard box and transported on pallets. In each case the operator of the inserter machine takes a cardboard box, opens it, removes the envelopes by gripping the outermost envelopes from the outside with his two hands and firmly holding them between his hands, placing the thus obtained stack onto the feed band or into the feed channel of the feed mechanism, placing them against the preceding envelopes and then disposing of the now empty cardboard box.
This handling is relatively expensive, since the opening of the box and the removal requires time. The respective gripping of the stack of envelopes dependent on the operator between two hands has the risk of mishandling actions and in individual cases can also cause some envelopes to be bent, so that the entire cycle of the inserter machine is stopped for this reason. The disposal process for the cardboard boxes that are still quite bulky even in empty state is also troublesome, since in this state they occupy a relatively large amount of space and therefore there quickly result stacks of boxes that are difficult to handle.
So-called Post Boxes have come into use for insertion envelopes as an alternative. These Post Boxes actually serve to transport conventional filled letter envelopes by Deutsche Post AG, for example, but can also be used to temporarily accommodate insertion envelopes. These Post Boxes form a type of upwardly open trough, into which an operator of the inserter machine or possibly also an automated device can reach and remove the stack of insertion envelopes and place them into the feed channel or onto the feed belt of the feed mechanism of the inserter machine.
These Post Boxes are made of plastic and are reusable and, as mentioned, can also be used for other purposes, which keeps the piece numbers high and therefore the production and storage costs within feasible limits despite the very complex structure. Because of their shape, they can be stacked in a relatively space-saving manner, however, these Post Boxes also take up a relatively large amount of space and are also heavy after emptying and are still comparatively expensive to produce.
As an alternative to these Post Boxes, cardboard packaging arrangements are proposed in patents EP 1 160 170 A2 and EP 1 731 433 A1, which like the Post Boxes are stackable and can be handled in a similar form. They have the advantage of being slightly more space-saving and also lighter both in empty and in filled state, and therefore also allow a more favourable transport and removal. These cardboard containers are also reusable and therefore environmentally friendly. This environmentally friendly aspect is further improved by the use of cardboard in the production instead of plastic.
A further possibility of packaging insertion envelopes is proposed in patent EP 1 352 845 B1. There, a stack of insertion envelopes is completely enclosed by an elastic film of plastic material over the short side edges of the envelopes, wherein two plastic panel members are additionally provided to reinforce the first and last envelope in order to increase stability and prevent the corners of the envelopes from bending over. The operator grips such a plastic packaging, lifts it up, laterally slits open the film, removes this, takes the plastic panel members and disposes of these separately and places the stack on the feed belt.
This proposal has the disadvantage that the handling is very complicated. In each case, the operator must slit open the film and remove the opened film while manually holding the packaging together with the envelopes over the feed belt. Thus, he only has his two hands for holding and slitting and therefore must have considerable dexterity to conduct this operation.
The operator could also try to press the envelopes out of the downwardly open plastic packaging. He also needs both hands for this, since he must hold the plastic packaging firmly and press the envelopes, and therefore requires considerable dexterity to simultaneously also correctly select the location to which the pressed out envelopes should then be directed. Moreover, this procedure results in a substantial risk of the corners or side edges of the pressed out envelopes being bent over or damaged or of the envelopes lying closest to the plastic panel members being caught on the plastic panel members, and there also being damaged and, therefore, disruptions to the operating cycle resulting.
The flaps of the insertion envelopes to be opened are also particularly at risk.
Moreover, the material is again plastic, i.e. a film-type plastic for the covering and also a thermoplastic for the reinforcement, which must be disposed of separately or must be further treated. If the thermoplastic used heats up during storage and transport, particularly because of the film-type plastic covering, then there can result distortions of the packaging and its contents and therefore bent envelopes that cannot be optimally aligned. Moreover, the sensitive upper and lower longitudinal edges of the envelopes in particular are unprotected.
Despite the different advantages of the possible packaging arrangements for insertion envelopes known from practice, therefore, there is still a requirement for further proposals to allow as secure and reliable a supply as possible of such insertion envelopes to inserter machines.